Theory of Substituent Effects: Recent Advances

The review reports recent progress in the studies of substituent effects in isolated molecules, i. e. based either on the experimental gas-phase acidities (basicities), or on quantum chemical calculations. Attention was focused on cases when the results differed from or exceeded the traditional views: redefinition of the inductive effect, quantitative estimation of resonance, validity of the Hammett equation, interpretation of the ortho effect, additivity of the enthalpies of formation, acidity of carboxylic acids.